Sulfonic acid surface active agent and method of preparation



Patented Apr. 10, 1951 SULFONIC ACID SURFACE ACTIVE AGENT AND METHOD OF PREPARATION Glen W. Hedrick, Glen Ellyn, 111., assignor to E. F. Houghton and Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application October 12, 1948, Serial No. 54,210

12 Claims. 1

The present invention relates to novel surface active agents and more particularly, it relates to surface active agents having marked wetting properties, as well as other desirable properties, comprising a new type of chemical substance, namely, the water soluble salts of aroyl sulpho propionic acid esters containing two or more condensed carbocyclic rings in the aryl group as more fully described hereinafter. This application is a continuation-in-part of application Serial No. 626,438, filed November 2, 1945, now abandoned.

The principal object of the invention is to provide surface active agents having outstanding wetting properties, which agents may be used wherever such properties are desired, for example, in processing textile fibres and fabrics,

- leather, paper and other fibrous materials, in

cleaning processes, such as general household cleaning, material cleaning, dishwashing, and the like, and in frothing, emulsifying, emulsion breaking, flotation, and other processes. The agents are especially useful to increase the waterabsorptivity of fibrous or other materials, and therefore, the wetting agents of the invention may advantageously be used in the kier boiling of cotton, in the scouring of wool, in the boilingoff of rayon, in dye baths, as assistants in the production of Sanforized cotton, in the fatliquoring of leather, in the treatment of paper, and the like.

Other objects, including the provision of a novel method of producing the wetting agents of the invention, will be apparent from a consideration of the specification and the claims.

As indicated above, the wetting agents of the present invention comprise the water soluble salts of certain aroyl sulpho propionic acid esters, the aroyl radical being defined as a radical of the type RCO- where R is a condensed ring system of the type hereinafter set forth.

The surface active agents of the present invention are represented by the formula: o

H II A-c-1 3 o-oR2 where A is a polycylic condensed ring system selected from the group consisting of naphthyl, monochloronaphthyl, monoalkyl naphthyl, the alkyl group of which contains from 1 to 11 carbon atoms, monochlormethylnaphthyl, dialkyl naphthyl, the alkyl groups of which contain no more than carbon atoms, tetrahydronaphthyl, acenaphthyl, and fiuorenyl; where B is an ethylene group; where R2 is an alkyl group containing from 1 to 12 carbon atoms; where M is a cation providing water-solubility to the product; and Where the total number of carbon atoms of R2 plus carbon atoms in a substituted alkyl group or groups in the aryl group A (i. e. where A is monoalkyl naphthyl, dialkyl naphthyl or monochlormethylnaphthyl) is at least 4 but not more than 12.

In the above formula, no attempt has been made to indicate to which of the two carbon atoms in the ethylene (B) group the sulpho group (SO3M) is attached. The most practical chemical processes, however, for introducing the sulpho group into this ethylene linkage are believed to produce mixtures rather than pure alpha or beta derivatives. Generally, while the alpha derivative is believed to predominate, the location of the sulpho group is immaterial since it must exert a similar hydrophilic action on the molecule either in the alpha or the beta position, and it is to be understood that both the alpha and. beta compounds, and mixtures thereof, are within the scope of the invention.

As pointed out in connecton with the formula, M is a cation rendering the compound Watersoluble, for example, an alkali metal such as sodium or potassium, the ammonium radical and the like.

The products of the present invention thus embody not only a polycyclic condensed ring group of the type described but also a definite number of exterior or external carbon atoms. As stated, these external carbon atoms must total at least 4 and not more than 12. Some or all of these external carbon atoms may be provided by an alkyl ester group, R2. When the condensed ring nucleus (A) is selected from the group consisting of naphthyl, monochloronaphthyl, tetrahydronaphthyl, acenaphthyl, and fiuorenyl, all exterior carbon atoms are provided by the R2 group, in which case R2 contains from 4 to 12 carbon atoms. When the condensed ring nucleus is an alkyl substituted naphthyl group, some of these external carbon atoms may be provided by the substituted alkyl group attached to the naphthyl nucleus, and as indicated, when the alkyl substituted naphthyl group is a monoalkylnaphthyl such substituted group may contain from 1 to 11 carbon atoms, and when it is a dialkyl naphthyl group, the alkyl groups may contain from 1 to 10 carbon atoms. From the standpoint of the present invention it is relatively immaterial whether any of the various alkyl groups is a straight or branched chain alkyl group. If the condensed ring nucleus is naphthyl or methylnaphthyl, a chlorine atommay also be attached to the nucleus without altering the properties of the compound significantly. Referring to the case Where the condensed ring nucleus is a naphthyl group, since the total number of external carbon atoms ranges from 4 to 12, for each ester group (R2) employed, there is a definite range of carbon atoms that may be present in any alkyl group or groups attached to the naphthyl nucleus and vice versa. For example, if there are no groups containing carbon atoms attached to the naphthyl nucleus (i. e. A is naphthyl or monochloronaphthyl) the alkyl ester groups are restricted to the butyl through the d'odecyl groups; while if, for example, a nonyl groupis attached to the naphthyl nucleus (i. e. A is nonyl naphthyl) the ester group is restricted to the methyl through the propyl groups. For the sake of simplicity, the above described polycyclic condensed ring system group, A, Will be referred to herein as an aryl derivative, and the group as an aroyl derivative.

While numerous specific compounds may be prepared by the methods hereinafter described corresponding to the formula given for the compounds of the invention, they will possess marked wetting properties, making them available for use as surface active agents in the various industrial fields. This is because such compounds embody the structure hereinabove set forth as well as external carbon atoms Within the stated limits, and the specific examples hereinafter set forth demonstrate the fact that such compounds possess marked Wetting properties.

The compounds of the invention possessing wetting properties to the highest degree are those corresponding to the formula:

where A is a condensed bicyclic group selected from the group consisting of naphthyl, methyl naphthyl and tetrahydronaphthyl; where R2 is an alkyl group containing from 8 to 10 carbon atoms, and where B and M are as stated above. Preferably R2 is an alkyl group containing 8 carbon atoms, and M is sodium.

The products of the invention may be readily and economically prepared by condensing the de: sired aryl derivative reactive in a Friedel-Crafts acylation type of reaction, with the anhydride of a four carbon atom dicarboxylic aliphatic acid, i. e. maleic anhydride or succinic anhydride; esterifying the resultingacid; and then converting the ester into the sulpho derivative, as will be further discussed hereinafter. Another, but not preferred method of preparing the products of the present invention is by condensing a half ester-half acid chloride of the four carbon atom dibasic acid with the aryl derivative to provide the ester, and then converting the ester into the sulpho derivative.

In preparing the aroyl derivative, the desired aryl derivative furnishing not only the condensed ring system nucleus of A, but also any substituted alkyl group or groups, is reacted by aFriedel- Crafts acylation reaction with a molar equivalent of the anhydride. ihe aryl derivative may be obtained from any source, for instance from coal 4 tar, petroleum or from synthetic processes. For example, in the case of alkylated naphthyl derivatives, these may be obtained by condensing naphthalene with an alkyl halide or with an aliphatic olefin by a preliminary Friedel-Crafts alkylation reaction.

Examples of the aryl derivatives that may be used in the preparation of the aroyl derivatives in accordance with the present invention are: naphthalene;- monochloronaphthalene; monochloromethylnaphthalene; the monoalkyl naphthalenes such as methylnaphthalene, isopropyl naphthalene, secondary butylnaphthalene, nbutyl naphthalene, the amyl naphthalenes, the hexylnaphthalenes, the octylnaphthalenes, the nonylnaphthalenes, the decylnaphthalenes, and the like; the dialkyl naphthalenes such as dimethyl naphthalene, diethylnaphthalene, di-isopropylnaphthalene, dibutylnaphthalene, the diamylnaphthalenes, decylmethylnaphthalene, the octylethylnaphthalenes, and the like; tetrahydronaphthalene; acenaphthylene; and fiuorene.

The anhydride of the four carbon atom dicare bo xylic aliphatic acid may be the unsaturated maleic anhydride or the saturated succinic an= hydride. When maleic anhydride is employed, the aroyl compound prior to sulphonation is an aroyl acrylic acid ester. Upon sulphite addition, the double bond is saturated and the product is a water soluble salt of an aroyl sulpho propionic acid ester, wherein the SOaM group has become attached to one of the carbon atoms of the Cll=CI-I group, and a hydrogen atom to the other. In the case of succinic anhydride, the aroyl derivative of propionic acid is formed as a result of the Friedel-Crafts reaction, and a hydrogen atom attached either to the alpha or beta carbon atom must be substituted by the sulpho group as hereinafter described.

The reaction between the aryl derivative and the anhydride to form the corresponding aroyl acrylic or propionic acid is brought about, as has been stated above, by a Friedel-Crafts acylation reaction, and any of the various expedients used in that type of reaction may be employed in the production of the aroyl compound. Advantageously,the condensation is brought about by condensing the aryl derivative with approximately a molar equivalent of the anhydride in a suitable solvent with anhydrous or substantially anhydrous aluminum chloride. While the solvent employed may in some cases, be an excess of the aryl derivative, the use of a suitable inert solvent such as carbon disulphide, orthodichlorobenzene, methylene chloride, ethylene chloride, and tetrachloroethane is preferred.

The aryl derivative and the anhydride may be mixed with the solvent and the aluminum chloride added thereto, preferably gradually over a period of time, or the anhydride may be mixed with the aluminum chloride and solvent and the aryl derivative may then be added, preferably gradually. Other procedures for bringing together the aryl derivative, the anhydride, the solvent, and the aluminum chloride may of course be used, if desired. The reaction, at least at the start, is exothermic and hydrogen chloride is evolved as the reaction proceeds. The reacting mixture is generally maintained at a temperature in the range from about 20 C. to about 65) C. by cooling at the start and by heating subsequently if necessary, and it is advantageousto agitate the mixture during the reaction.

h the ond at n s ompleted. which may be determined by cessation of the evolution of the hydrogen chloride, the mass may be poured into ice, water and a small amount of mineral acid, keeping the mass cold as is the usual practice in the type of reaction, and the mixture may be agitated until the aluminum chloride complex is decomposed. The condensation product which is in solution in the solvent may then be separated from the aqueous phase and washed with water and mineral acid to remove the salts of aluminum.

The aroyl acrylic or propionic acid may be isolated by either extracting it from the solvent with a warm 5% soda ash solution or by removin the solvent by distillation. The acid may be purified by dissolving it in a solution of a suitable alkali, such as soda ash, filtering to remove any insoluble material and precipitating the acid by the addition of mineral acid.

In one procedure, the aryl derivative is dissolved in an inert solvent and about one molecular equivalent of maleic anhydride is added to the solution. The mixture is heated to a temperature at which the aluminum chloride complex remains dispersed, for example, to about 40 C., and is maintained between that temperature and about 50 C. during the reaction. The aluminum chloride (about 2 molecular equivalents) is added gradually, for example, in portions during the reaction, and the mass is agitated during the reaction. When the reaction is complete, which may require several hours-for example, six hours-the aluminum chloride complex is decomposed and the acid isolated as above described.

In a more preferred procedure, the aluminum chloride, anhydride and a chlorinated solvent are mixed, and the mixture i agitated and becomes uniform. The aryl derivative is gradually added at a temperature between about 40 C. and about 50 C., and after the addition is completed, the mixture is stirred for a short period at a temperature between about 40 C., and about 60 C. The aluminum chloride complex is decomposed and the acid isolated as above-described.

The aroyl acrylic or propionic acid is esterified with a compound providing the desired R2 group, and the resulting ester i then converted to the sulpho derivative. The alkyl ester of the acid may be prepared by any of the suitable esterifying reactions.

In one type of method, the ester is formed by reacting the acid with one molecular equivalent of the alcohol corresponding to the alkyl ester desired in the presence of a solvent and an esterifying catalyst such as concentrated sulphuric acid, benzeneor toluene-sulphonic acid. Preferably, the solvent is one which like toluene, boils slightly above the boiling point of water. The mixture of the aroyl acrylic or propionic acid, the

'alcohol,.the solvent and the esterification catalyst are boiled and the water formed by the esterification reaction is removed. After the esterification reaction has been completed, the ester, which is in solution in the solvent, may be washed with water, followed in some cases by dilute alkali 'to remove any unconverted acid and thetraces of catalyst. The ester may be isolated by removing the solvent by steam distillation, distillation at atmospheric pressure or by evaporation in vacuo.

In another type of esterification procedure to produce compounds in which R2 isa small alkyl group, the ester of the aroyl'acrylic or propionic acidmay be obtained by dissolving the acid in .a solvent such as toluene, benzene, chlorbenzene, prthodichlorobenzene, carbon tetrachloride, tetrachlorethane, and the like. The acid is then converted into a salt and the ester formed by reaction with an alkyl sulphate, the alkyl group of which corresponds to the ester desired. In such a process, the alt is advantageously formed by the addition of a slurry of soda ash in water, and in such a case, foaming occurs due to the evolution of carbon dioxide, and the mass becomes thick and has the appearance of a clear gel. The reaction between the salt of the acid and the alkyl ulphate is exothermic and is completed within a few minutes, as shown by the fact that a sample mixed with water separates readily into two layers. The mass obtained as the result of the reaction is made acid by the addition of mineral acid, is washed with water to remove the salts and the ester is obtained upon removal of the solvent by steam or vacuum distillation.

, The aroyl acrylic or propionic acid ester may be converted into the sulpho derivative by any process by which the SO3--M group may be attached to one of the carbon atoms of the vinylene or ethylene chain of the acrylic or propionic ester. Preferably, when an aroyl acrylic acid ester is employed, the sulphonation is brought about by reacting the ester with a bisulphite such as sodium, potassium or ammonium bisulphite. In the sulphonation reaction, the ester is mixed with the bisulphite dissolved in water or other solvent, for example, a mixture of equal parts of water and ethyl alcohol. The bisulphite employed is sufficient to convert the ester into the sodium or other salt of the sulphonic acid, the use of a slight excess of the bisulphite often being advantageous. The mixture is advantageously heated in a closed. container equipped with an agitator. until the ester becomes completely soluble in water. The temperature of heating will depend on the particular ester being treated and usually a temperature between about 80 C and 110 C. will be employed, and in many instances it will be desirable to heat the mixture to boiling. The ester is rendered completely soluble in water by this treatment and the product formed is the sulphonic acid salt of the cation of the bisulphite. Thus, as stated in connection with the formula, M may be any cation which provides watersolubility, for example, an alkali metal ion, ammonium radical or the like.

Referring to the saturated aroyl propionic acid ester it may be first converted into a halogenated derivative, for example, a bromo compound, prior to sulphonation. In such conversion process, the ester is advantageously dissolved in a solvent and a small amount of a halogenating catalyst such as phosphorus trichloride is added. The halogen, for example, bromine, is then brought into contact with the solution, for instance, by adding liquid bromide drop-by-drop to the solution. Hydrogen halide is liberated and the reaction is completed in a short time. The halogenated derivative is isolated by evaporation of the solvent. The halogenated derivative thus prepared may then be sulphonated byreacting the halogen derivative with a sulphite, for example, sodium or potassium sulphite, to replace the halogen atom of the compound with the SO3M group. Advantageously, the reaction is brought about by refluxing an aqueous mixture of the reactants until the reaction has progressed to completion. As in the case of the products obtained by the previously described method of sulphonation, the sulphonated product may be Iprovided with the desired cation represented In. order: to. illustrate the invention. further; the following specific examples are given forsthe preparation of the compounds .of. the; present. ine vention. Three diiierent procedures were. em.- ployed in preparing the compounds of the examples and are illustrated below as Methods: A. B; and C, respectively. Each of the numerical ex,- amples, from 1 to 21, inclusive, was.made. ac.- cording toone of these three methods, and: to avoid: repetition of the details of. theprocedures; each of theseexamples is designated as towhich method was followed. In each case; a measure. of the compounds surface activity-is given .by show.- ing wetting speeds at various concentrations in waterdetermined by the time required to; wet out a" Bgram -skein of raw cotton yarnat 100. E; according to the standard Draves method:

METHOD A The preparation of the methyl ester ofnonylnaphthoyl sulpho propionic acid, sodium salt The mixture of 49 g. /2 mol) of maleic anhydride. and 105, g. aluminum chloride, there are added. 90 cc. ethylene. chloride. The suspension isagitateda-nd water cooled. After most. of the solids. have dissolved, 127 g. /2 mol) of nonyl naphthalene (1,3,5 trimethylhexylnaphthalene) areadded slowly. After the, addition, the mixture isstirred for 3ulminutes at 50 C. The material is then cooled and; decomposed with a mixture of; 450, g. crushed ice, 50 cc. of 66% sulphuric. acid; and; cc. isopropanol. After most of thedark, brown complex has been decomposed. the mixture is heated to reflux temperature. After five minutes of refluxing, the material is split. The. lower layer is discarded. The upper layer is: then washed twice with '70 cc. portions of 66% sulphuric acid. Seventeen cc. of methanol and 12 cc. of concentrated sulphuric acid are added to the ethylene chloride solution of the maleic anhydride condensate and the material isrefiuxed for 45 minutes. The lower layer is then drawn off and another 12 cc. of methanol and 8 cc. of concentrated sulphuric. acid are added, andrrefiuxing is continued, ior'another' 9.0 minutes. The lower layer is again: drawnoff and-the. solvent is. distilled off from the organic solution. The. last traces of solvent are removed under vacuum and heating is continued ,until the'temperature within the. liquid. has risen to 125-6. The liquid is. thenallowed to cool somewhat and a solution of l g. sodium hydroxide and 55 g. sodium bisulphite in 250 cc. of water is added to the oil. The mixture is stirred and heated to 95 C. temperature is maintained there for one hour although the sulphonationreaction is usually completed after ten minutes. The productgave a: wetting; speed of 33 seconds at aconcentration of .1%.

METHOD B napthoyl sulpho propionic acid, sodium salt To a mixture. of 49 g. /2 mol) maleic anhydride; and 105; g; aluminum chloride,. there are added-90 cc. of. ethylene chloride. The suspension is: agitated. and water cooled. After most ofthe solids have dissolved 64 g. /2. mol) naphthalene are added, slowly.. After the addition, the mixture is stirred for minutes at 50 C. Thematerial is then cooled and decomposed with a mixture of 500 g. crushed ice, 100 cc. 66% sulphuric acid, and 65g. mol) 2-ethylhexanol. The mixture; is stirred for 90 minutes at room temperature. The lower layer is then drawn oil.

1: cc.-.. of: concentrated sulphuric: acid; is added. to the. organic .layeiz-whichis thenrefluxed through a..constant..waterseparator for 2.hours or longer until: practically ally of: the acid has been esterified; Thesolventis distilled off until the temperature Within. the. oil. has, reached. C. A solution of. 52g, sodium bisulphite and 1. g, sodium. hydroxide; 110 cc. of. water is added to the oil. The. agitated. mixture is heated to 105 C. and is maintained there for 15.- minutes, after; which time. sulphonation is complete. The isolatedv product. at, a; concentration of, .05%,-. in water:providedawetting speed of 21 seconds,

rahydronaphtlmyl; sulpho propiornic. acid, so.- dium salt To' a cooled and stirred mixture of 40' gr /2 molimaleicanhyd'ride. 66g. mol) tetrahydronaphthalene and 300 cc. O-diehlorobenzene, there are added gradually in small portions. g; aluminum chloride. The temperature is allowed to rise slowly to 50 0-60 C; where itzis maintained until no more hydrogen chloride is given off. l he material is-decomposedby pouring-it over-1 kg; of'crushedice towhich lfl'fl cc. of concentrated sulphuric acid hadbeen added. The mixture isstirred-until the aluminumchloride complex has been broken up completely. Then the lower layer is drawn off and the sol.- vent is steam-distilled off from the upper layer. The steam distillation residue taken upin. a mixtureof ZOOcc; of tolueneand' IO-g; 2-ethylhexanoland any lower layer which may be iormed isdrawn' off; The solution is then re! fi'uxed with 10 cc. of concentratedsulphuric acid through a constant water separator until practically all. of the acid is esterified which re..- quires' about 4- liours. The bottom layer is then drawn off and any mineral acid present in the oil is. neutralized; The toluene is steam-distilled off. The ester is then sulphonatedasdesoribed under Method B. The product. gave. awetting speed of 16 seconds ata concentration of: .05i% inwater;

Other water soluble salts instead of the sodium salts, such as the potassium or ammonium salts, may be prepared by employing potassium or ammoniumbisulphite inthe: above methods in place of the: sodium .bisulphite. These other. water isoluble salts. exhibit strong surface activeproper ties, and may. be used inv a manner; similar. to the sodium salts.

In. the; following; examples,-. the sodiumsalt of the; ar.oy11.sulpho. propionic acid, esters is pre pared, but as. previously set forth,. othenwater soluble..salts;,such as-the potassium or: theammonium .saltsmay be: prepared by analogous-1pm.- cedures;

EXAMPLE 1v Thesaltof-tlien-butyl ester ofnaphth'oyl' sul-- pho. propionic .acid' was prepared following Method-Bby firstcondensing' naphthalene with maleic anhydride. The naphthoylacrylic acid thus formed'was esterified with n-butyl alcohol; and the'resulting' ester was reacted with sodium bisulphiteto form the sulpho derivative. At a concentration of 0.1%, the compound gave a'wettingspeed'of 40 seconds.

EXAMPLE 2 The saltof the lauryl ester of naphthoyl. sul"- plio propionicacid *was prepared following;Method Bbyfirst condensing:naphthalene with maleic 9 anhydride. formed was esterified with lauryl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.25%, the compound gave a wetting speed of 50 seconds and possessed detergent properties.

EXAMPLE 3 The salt of the 2-ethylhexyl ester of alpha monochloronaphthoyl sulpho propionic acid was prepared following Method B by first condensing alpha-chloronaphthalene with maleic anhydride. The chloronaphthoyl acrylic acid thus formed was esterified with Z-ethylhexyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of it gave a wetting speed of 14 seconds.

EXAMPLE 4 The salt of the n-propyl ester of alpha-methylnaphthoyl sulphopropionic acid was prepared following Method A by first condensing alphamethyl naphthalene with maleic anhydride. The alpha-methylnaphthoyl acrylic acid thus formed was esterified with n-propyl alcohol and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At'a concentration of 0.1%, it gave a wetting speed of 35 seconcls.

EXAMPLE 5 The salt of the 2-ethylhexyl ester of alphamethylnaphthoyl sulpho propionic acid was pre pared following Method B, by first condensing alpha-methyl naphthalene with maleic anhydride. The alpha-methylnaphthoyl acrylic acid thus formed was esterified with 2-ethylhexyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 1.75%, it gave a' wetting speed of 12 seconds, and at a concentration of 03%, a wetting speed of 42 seconds.

EXAMPLE 6 EXAMPLE '7 The salt of the n-hexyl ester of hexylnaphthoyl (1,3 dimethylbutylnaphthoyl) sulpho propionic acid was prepared following Method B by first condensing hexylnaphthalene (1,3 dimethylbutylnaphthalene) with maleic anhydride. The hexylnaphthoyl acrylic acid thus formed was esterified with n-hexyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.2%, the compound gave a wetting speed of 25 seconds.

EXAMPLE 8 The salt of the methyl ester of nonylnaphthoyl (1,3,5 trimethylhexylnaphthoyl) sulpho propionic acid was prepared following Method A by first condensing nonylnaphthalene (1,3,5 trimethylhexylnaphthalene) withmaleic anhydride. The nonylnaphthoyl acrylic acid thus formed is ester-.

The naphthoyl acrylic acid thus EXAMPLE 9 The salt of the methyl ester of decylnaphthoyl sulpho propionic acid was prepared by first preparing the decylnaphthoyl acrylic acid, from technical decylnaphthalene, as in Method C. One molecular equivalent of the acid was then dissolved in about 760 cc. of toluene. To this solution was added slowly while agitating a slurry of 63.5 gms. of soda ash in 63.5 cc. of water at a temperature of about70 C. Foaming occurs, and the mass becomes thick.

To this isadded dropwise at 70 0., 138 gms. of dimethyl sulphate. The reaction is exothermic and is complete within a few minutes. The mass is made acid by the addition of mineral acid, washed to. remove salts and the solvent distilled by steam or in vacuo.

The methyl ester thus obtained is reacted with sodium bisulphite to form the sulpho derivative. The product had good foaming and wetting properties. At a concentration of 0.1% it gave a wetting speed of 41 seconds.

EXAMPLE 10 EXAMPLE 11 I The salt of the ethyl ester of dimethylnaphthoyl sulpho propionic acid was prepared following Method A by first condensing dimethylnaph thalene with maleic anhydride. The dimethylnaphthoyl acrylic acid thus formed was esterified with ethyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.3%, the compound gave a wetting speed of 30 seconds.

EXAMPLE 12 The salt of the n-decyl ester of dimethylnaphthoyl-sulpho propionic acid was prepared following Method B by first condensing dimethylnaphthalene with maleic anhydride. The dimethylnaphthoyl acrylic acid thus formed was esterified with n-decyl alcohol and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.1%, the compound gave a wetting speed of 14 seconds.

dium .bisulphite to form the sulpho derivative. i At a concentration of .l%, itgave awetting speed 0f QB Second .EXAMELE .15

The salt of the "n-b'utyl ester of tetrahydronaphthoyl sulpho propionic acid was prepared following Method B by-first'condensing'tetrahydronaphthalene with maleic anhydride. The tetrahydronaphthoyl acrylic acid ';thus formed was 'esterified with n-butyl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.1%, the compound gave a wetting speed of seconds.

EXAMPLE 11.6

The salt of the n-octyl ester-of tetrahydronaphthoyl sulpho propionic acid was prepared following Method ,B by first tcondensing tetrahydronaphthvlene with maleic anhydride. The

tetrahydronaphthoyl acrylic acid thus formed was esterified wi h .n-..0c. y1 alc hol, a d h resui in est r was reacted with sodium bisu phite to form th ulpho derivative. .At .aconcentration of 70.1% it gavea wett ng s eed 0L8 seconds.

I EXAMPLE 17 The :salt of the lauryl ester of .tetrahydronaphthoyl sulpho propionic acid was prepared following Method B .by first condensing tetrahydronaphthalene with maleic anhydride. The tetrah-ydronaphthoyl acrylic acid thus formed was esterified with lauryl alcohol, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.2%, the compound gave -a wetting speed of seconds and possessed marked'detergent and foaming properties.

The salt of the butyl ester of acenaphthoyl sulpho propionic acid was prepared following Method B by first condensing acenaphthalene with maleic anhydride. The acenaphthoyl acrylic acid :thus formed was esterified with n-butyl alcohol, and the resultingester was reacted with sodium bisulphite to form the sulpho derivative. A a concentrati n-0f 0 th compound gavea wettin speed-of 25 second EXAMPLE .19

EXAMPLE 20 L'he salt of the n-butyl ester of fiuorenoyl sulpho propionic acid was prepared following Method B by first condensing fluorene with maleic anhydrid The fi orenoyl acryli acid thus form d 1 2 was esterified with n butyl alcohol, and -=the resulting ester wasreacted with sodium'hisulphite to form the sulpho derivative. The compound gave a wetting'speed of 30 seconds at 0.1% concentration.

EXAMPLE '21 The salt of the lauryl ester of fiuorenoyl sulpho propionic acid Was prepared following Method B by first condensing -fiuorene with malei-c anhydride. The fiuorenoyl acrylic acid thus formed was esterified with lauryl alcohol, and the resulting ester was :reacted with sodium bisulphite to form the sulpho derivative. At a concentration of 0.2%, the compound gave a wetting speed of 50 seconds.

Of the foregoing compounds, the water soluble salts of the octyl esters of naphthoyl sulpho propionic acid, and more specifically the sodium salt of the 2-ethyl hexyl ester of naphthoyl sulpho propionic acid; the water soluble salts of the octyl esters of methylnaphthoyl sulpho propionic acid and more specifically thesodium salt of the 2-ethyl hexyl ester of methyl naphthoylsulpho propionic acid; and the water soluble salts of the octyl esters of 'tetrahydronaphthoyl sulpho propionic acid, and more specifically the sodium salt of the Z-ethylhexyl ester of tetrahydronaphthoyl sulpho propionic acid and the sodium salt of the n-octyl ester of tetrahydronaphthoyl sulpho propicnic acid. are preferred.

Considerable modification is possible in the preparation of the products as well as in the various combinations .{Of ,A, B2, d M without departing from thescope of the-present invention.

Iclaim:

1. As a surface active agent possessing marked wetti e properties, .a water soluble salt of an aroyl sulpho propionicacid ester corresponding to the following formula:

where A is a polycyclic condensed ring system selected from the group consisting of naphthyl', monochlornaphthyl, monoalkylnaphthyl, the alkyl group of which contains from 1 to 11 carbon atoms, monochlormethylnaphthyl, dialkylnaphthyl, the alkyl groups of which contain no more than 10 carbon atoms, tetrahydronaphthyl, acenaphthyl and fluorenyl; where B is an ethylene group; where R2 is an alkyl group con taining from 1 to 12 carbon atoms; where M is a cation providing water solubility to the product; and where the total number of carbon atoms of R2 plus carbon atoms in a substituted alkyl group or groups in A is at least 4 but not more than 12.

2. The product of claim 1 wherein M is sodium.

.3. As a surface active agent possessing marked wetiting'properties a water soluble salt of an aroyl sulpho propionic acid corresponding to the following formula:

where A is condensed bicyclic group selected from the group consisting of naphthyl, methylnapthyl and tetrahydronaphthyl; where R2 is an alkyl. group containing from 3 to 10 carbon atoms; where B is an ethylene group; and where M is a cation providing water solubility to the product.

octyl ester of methylnaphthoyl sulpho propionic acid.

8. Asa surface active agent possessing marked wetting properties, the sodium salt of the 2- ethylhexyl ester of methylnaphthoyl sulpho propionic acid.

9. As a surface active agent possessing marked wetting properties, a water soluble salt of an octyl ester of tetrahydronaphthoyl sulpho propionic acid.

10. As a surface active agent possessing marked wetting properties, the sodium salt of an octyl ester of tetrahydronaphthoyl sulpho propionic acid.

11. As a surface active agent possessing marked wetting properties, the sodium salt of the 2-ethylhexyl ester of tetrahydronaphthoyl sulpho propionic acid.

12. The method of preparing a surface active agent possessing marked wetting properties which comprise condensing in a Friedel-crafts acylation reaction a polycyclic condensed ring compound selected from the group consisting of naphthalene, monochloronaphthalene, monoalkylnaphthalene, the alkyl group of which contains from 1 to 11 carbon atoms, monochloromethylnaphthalene, dialkylnaphthalene, the alkyl groups of which contain no more than 10 carbon atoms, tetrahydronaphthalene, acenaphthalene and fiuorene with maleic anhydride to form the corresponding aroyl acrylic acid, esterifying the resulting acid with a compound providing an alkyl ester group containing from 1 to 12 carbon atoms which provides, along with carbon atoms supplied by alkyl groups attached to the aryl nucleus of said polycyclic condensed ring compound, a total of from 4 to 12 carbon atoms, and reacting said ester with sodium bisulphite at a temperature between about C. and about C. to form the sodium salt of an aroyl sulpho propionic acid ester.

' GLEN W. HEDRICK;

REFERENCES CITED The following references are of record in the file of this patent:

Bogert et al.: J.A.C.S., vol. 47, pp. 526-535 (1925). 

1. AS A SURFACE ACTIVE AGENT POSSESSING MARKED WETTING PROPERTIES, A WATER SOLUBLE SALT OF AN AROYL SULPHO PROPLONIC ACID ESTER CORRESPONDING TO THE FOLLOWING FORMULA: 